Tropical Malaysia Research Articles

Cell Temperature Determination based on IEC61215: Solar Photovoltaic Experimental Study of Tropical Malaysia

Most commercial photovoltaic (PV) module data sheets include Nominal Operating Cell Temperature (NOCT) values, which assist PV system designers in estimating module temperatures under real outdoor conditions. However, the typical NOCT values of 45°C to 47°C do not account for tropical climates. This study seeks to develop an adjusted NOCT mathematical model and determine revised NOCT values suited for tropical conditions. The new proposed NOCT model follows the international standard IEC61215 but incorporates updated tropical Standard Reference Environment (SRE) parameters: solar irradiance (SI) of 800 W/m², ambient temperature (AT) of 31°C, and wind speed (WS) of 1 m/s. This modified NOCT model demonstrates improved accuracy over the existing model, with an average reduction of 2% in percentage error, root mean square error, and mean average percentage error. Outdoor NOCT testing conducted in Shah Alam, Malaysia, uncovered much higher NOCT values for various PV modules technology: 55°C for monocrystalline, 57°C for polycrystalline, and 59°C for thin film. These results emphasize the inadequacy of current NOCT values in commercial PV module data sheets, which do not accurately reflect conditions in tropical climates. The revised NOCT values from this study offer crucial thermal reference data for PV system designers, integrators, and researchers working in tropical regions, particularly Malaysia.

The Radiator

Abstract As a Chinese born and raised in tropical Malaysia, I had never seen a radiator before studying in the United Kingdom. Therefore, when I first arrived in the UK in the autumn, I embarrassingly mistook the panel radiator in my room for the place to hang my towel. To capture the experience, I wrote my poem in the shape of a panel radiator, a rectangle with two stands on the sides. Written vertically from right to left, the poem's form resembles the ancient Chinese texts. I chose this form because the UK's autumn reminded me of literary works from China about autumn. Both locales are “the North” for me: while the UK is in the Global North, China is in the North for Malaysians.

Exploring bundle bamboo split technique in bending dendrocalamus asper for landscape structure

Bamboo is one of the fastest-growing natural construction materials and is locally available in most developing countries, including South America, Africa, and Asia. Bamboo is a “green gold” plant in the tropical forest. It is a fast-growing monocotyledon species belonging to the Gramineae family (Bambusoideae) and requires a short time for re-production. Bamboo’s physical strength provides builders from ancient times until today an opportunity to use bamboo as a natural and sustainable construction material for building houses and structures. Due to its capability to bend, bamboo is the most preferred material in vernacular construction and lately in Southeast Asia countries which borne new trend in building design. The built-environment professionals, namely landscape architects, architects, and engineers in Malaysia, still lack knowledge of bamboo, especially on bending capabilities, as one of the sustainable construction materials. Less concern was given to researching the capabilities of bamboo’s ability to bend, even though its strength is more than steel and provides various design opportunities compared to other sustainable materials. Different types of bamboo present different strength capacities. Therefore, the aims of this research is to compare and determine their strength capacity, bending criteria and species suitability for design and construction in Malaysia. This paper collects published literature on experimental studies on the different methods of Hot and Cold Bending Methods which allow bamboo to bend to suit designer needs and concentrate on Malaysian Dendrocalamus asper (Buluh Betung), which considered as tough and durable species, as the primary construction material for landscape structures. Bundle Bamboo Split (BBS), identified as one of the bending techniques adopted for an experimental project, using BBS of 0.8m radius, produces a prototype for a landscape structure. The findings indicate observation of works by a team of craftsmen trained by an expert in bamboo construction who used to produce bamboo structures from Bali, Indonesia, highlighted tools and procedures in bamboo construction. In short, this paper will also enhance the use of bamboo as an accessible, durable, creative and sustainable construction material that represents the local identity of Tropical Malaysia Landscape Architecture.

Pollen morphology of selected tropical plants in Peninsular Malaysia and its implication in the paleoecological reconstruction of Southeast Asia

Marine pollen records from the southern South China Sea (SCS) have yielded critical information regarding epicontinental vegetation succession since the last glacial period, which involves understanding the role of tropical rainforests in driving climate change. However, the rich biodiversity and pollen taxa in Southeast Asia are challenging for palynological work, such as detecting pollen signals from various vegetation types and tracing the source areas of pollen grains deposited in the ocean; therefore, improving the taxonomic level of fossil pollen identification is significantly crucial for pollen analysis in tropical regions. To enrich modern pollen references of Southeast Asia, we observed the pollen morphology of 124 identified species (111 genera and 42 families) from tropical Malaysia using a light microscope and scanning electron microscope (SEM). The results show 19 pollen morphotypes, of which the tricolporate type occurs in half of the samples, reflecting the complexity of fossil pollen classification and identification. Pollen sculpture and aperture details of the selected taxa are clearly shown under SEM, which significantly improves the morphological understanding of tropical pollen (e.g., fabaceae, euphorbiaceae, and rubiaceae). This result presents the potential of extracting unique pollen signals to distinguish different vegetation types that contain many common species in Southeast Asia. It highlights the significance of improving pollen identification levels to clarify whether there was a widespread rainforest on the exposed continental shelf during the last glacial period in the southern SCS.

Hereditary analysis and genotype × environment interaction effects on growth and yield components of Bambara groundnut (Vigna subterranea (L.) Verdc.) over multi-environments

This investigation was carried out to explore G × E interaction for yield and its associated attributes in 30 Bambara groundnut genotypes across four environments in tropical Malaysia. Such evaluations are essential when the breeding program's objective is to choose genotypes with broad adaption and yield potential. Studies of trait relationships, variance components, mean performance, and genetic linkage are needed by breeders when designing, evaluating, and developing selection criteria for improving desired characteristics in breeding programs. The evaluation of breeding lines of Bambara groundnut for high yield across a wide range of environments is important for long-term production and food security. Each site's experiment employed a randomized complete block design with three replicates. Data on vegetative and yield component attributes were recorded. The analysis of variance revealed that there were highly significant (p ≤ 0.01) differences among the 30 genotypes for all variables evaluated. A highly significant and positive correlation was identified between yield per hectare and dry seed weight (0.940), hundred seed weight (0.844), fresh pod weight (0.832), and total pod weight (0.750); the estimated correlation between dry weight of pods and seed yield was 1.0. The environment was more important than genotype and G × E in determining yield and yield components.A total of 49% variation is covered by PC1 (33.9%) and PC2 (15.1%) and the genotypes formed five distinct clusters based on Ward hierarchical clustering (WHC) method. The genotypes S5G1, S5G3, S5G5, S5G6, S5G8, S5G7, S5G2, S5G4, S5G10, S5G13, S5G11, and S5G14 of clusters I, II, and III were closest to the ideal genotype with superior yield across the environments. The PCA variable loadings revealed that an index based on dry pod weight, hundred seed weight, number of total pods and fresh pod weight could be used as a selection criteria to improve seed yield of Bambara groundnut.

Unveiling Genetic Diversity, Characterization, and Selection of Bambara Groundnut (Vigna subterranea L. Verdc) Genotypes Reflecting Yield and Yield Components in Tropical Malaysia.

Addressing genetic diversity and application of appropriate breeding strategies are imperative for Bambara groundnut (Vigna subterranea L.) improvement as a newly introduced legume in Malaysia. It has become a “miracle lucrative” legume for Asia and Africa because of its drought resilience, excellent nutritional profiles, and versatile uses. This crop's progress has been limited owing to a lack of extensive research, marginalization, inadequate knowledge, and a lack of accessible funds, among other concerns. The expansion of this crop is reliant on the assessment and selection of unique and reliable breeding lines in various circumstances. Consequently, the goal of this work is to determine genetic diversity and the relationship between yield-contributing components in 44 Bambara groundnut accessions sourced from the Genebank of Institute of Tropical Agriculture and Food Security (ITAFoS) at Universiti Putra Malaysia (UPM). Three replications were used in the experiment, which was done using a randomized complete block design (RCBD). The data were subjected to ANOVA, PCA, correlation, and heat map cluster analysis; also, genetic parameters and broad-sense heritability estimation were carried out on recorded phenotypic descriptors. All of the investigated variables had a significant variance (p ≤ 0.05 or 0.01) according to the ANOVA results. Yield per hectare showed a positively strong to perfect significant correlation (0.75 ≤ r ≤ 1.00; p ≤ 0.01) with the yield components viz. fresh pod weight, hundred seed weight, dry pod weight, and dry seed weight. Interestingly, these traits had heritability ≥ 60% and genetic gain ≥ 20%, which can be beneficial for direct selection to this crop improvement. The UPGMA clustering revealed five distinct clusters in which genotypes under cluster I, cluster II, and cluster IV produce a greater yield of 5.96%, 7.12%, and 15.05%, respectively, than the grand mean yield of 1927.01 kg/ha. The PCA biplot estimated that PC1 (32.9%) and PC2 (12.9%) would cover 45.8% of the total variance. We discovered 30 promising lines that provide yields per hectare more than 1.8 ton/ha and might be used as parental lines in future breeding operations aimed at improving the grain yield in tropical areas or comparable agroecological zones.

RAIN FADE ANALYSIS AND LINK BUDGET PLANNING FOR 14.8-15.3 GHz TERRESTRIAL MICROWAVE LINKS OPERATING IN PENINSULA MALAYSIA

Most of the reported works on fade duration analyses were mainly based on the ITU-R method. Other related works were based on experimental radio links (less than 1 km path length) rather than actual operational radio links. However, empirical evidences have shown that ITU-R method is not excellently accurate for analyzing the link budgets of terrestrial microwave links operating in tropical and equatorial climates, hence the motivation for this study. The measured rain rate and attenuation on seven, geographically spread, terrestrial microwave links in tropical Malaysia are analysed in this article. The rain attenuation data were collected from 7 DIGI MINI-LINKs operating at Ku-band (14.8 – 15.3 GHz) with 99.95 % availability. The results were used to determine rain fade depth corresponding to a particular rain event on each of the links. The experimental results (attenuation, path reduction and receive signal level) were also compared with the ITU-R predictions. The fades predicted by ITU-R method are comparable to those obtained experimentally; however there is noticeable discrepancy between the experimental and ITU-R path reduction. The rain fade depth increases both with increasing path length and rain rate. More so, the RSLs predicted by the ITU-R method are higher compared to those of experimental values especially at extremely high rain rates, which is due to underestimation of the measured attenuation by the former. Therefore, the fade margins based on the ITU-R predictions come with low accuracy. This study is a useful tool for link budget design and planning of terrestrial radio links operating in Peninsula Malaysia and similar tropical equatorial climates.

Feasibility of Vertical Rainwater Harvesting via In-situ Measurement of Wind-driven Rain Loads on Building Facades in a Tropical Climate

Rainwater is an alternative water resource to fulfill sustainable management of freshwater particularly in the regions receive abundant annual amounts of precipitation such as tropical Malaysia. To collect and store rainwater, rainwater harvesting system has been practiced since ancient from horizontal surfaces mostly rooftop of buildings in urban areas. Nowadays, this method in modern urban areas with tall buildings is considered inadequate and uneconomical because the ratio of facade surface areas is much higher than the ratio of roof surface areas. On the other hand, all rain has a horizontal velocity due to wind acting upon rain droplets which is called wind-driven rain (WDR). Growing tall buildings and the presence of WDR phenomenon make building façade surfaces the available promising surfaces to harvest substantial rainwater vertically and more efficiently. This article presents a one-year field measurement results that aims at quantifying the WDR loads impinged on the vertical facade areas of a pilot building located at the main campus of the University Malaya in Kuala Lumpur, Malaysia. Detailed descriptions of the gauge design, building, the measurements of on-site WDR, rainfall duration time, and weather data are presented. Records show that monsoon winds characteristics have significant influence on the WDR loads on the building facades compare to horizontal rainfall intensity. Finally, the collected in-situ data are exploited to validate data and determine WDR coefficient (γ) to estimate the amount of WDR on a building façade via an empirical WDR relationship. Results show the feasibility of each square meter of vertical façade area to supply 12% of non-potable or 4.9% of potable water-usage per capita per day.

Revisiting Solar Photovoltaic Roadmap of Tropical Malaysia: Past, Present and Future

Environmental issues and economic factors such as emission of Greenhouse Gases (GHGs), fossil fuel depletion and fluctuation of oil prices are also the reason behind the utilization of sunlight as a source of energy. Even though with the spread of unprecedented pandemic of COVID 19, the industry of solar photovoltaic (PV) is surviving at a very promising rate compared to the oil industry. Malaysia has a high potential to be successful at harnessing solar energy as this country is located within the equatorial region. The government of Malaysia (GoM) introduced various policies, acts and incentives programs for the purpose of increasing this country’s potential to harness solar energy. Along with the efforts, goals and aims have also been set as a benchmark to measure Malaysia’s success in utilizing sunlight as an energy source. This study reviews the roadmap programs executed by GoM to elucidate the significant roles played in the development of solar PV starting from a few pilot projects in1980s until present. The roadmap focuses on incentive programs namely Feed-in Tariff (FiT), Net Energy Metering (NEM), Self-Consumption Scheme (SELCO), Large Solar Scale (LSS), Supply Agreement with Renewable Energy (SARE) and ‘Peer-to-Peer’ (P2P), which complement all the projects and solar PV applications in Malaysia. The contributing result of this roadmap is the highlights on the continuous solar PV programs stimulated by GoM, the identification and effort to improve the less performing GoM incentive programs combined with the positive responses from communities and industries, have laid a strong platform to forecast a promising future of solar PV industry in Malaysia.

Improving total sediment load prediction using genetic programming technique (Case Study: Malaysia)

Predicted total sediment load is usually used to identify the intensity of a sedimentation process. Currently, the existing available models to predict total load are mostly developed based on data collected from flumes, channels and rivers located in western countries. These models known as sediment transport model may not be valid to predict total sediment load of rivers in the tropics due to significant differences in the hydrological and sediment characteristics conditions. A new technique called Genetic programming (GP) technique is used to develop a new model to improve the prediction of total sediment load for rivers in tropical Malaysia. The new model named Evolutionary Polynomial Regression (EPR) model is compared with other three available sediment transport models using the different techniques including, Regression Equation, Modified Graf and Multiple Regression. Statistical analyses based on 82 data sets show the sediment transport model using this new technique perform well compare to other models.

Daily discharge simulation: combining semi-distributed GIS-based and artificial intelligence models

Developing highly accurate semi-distributed rainfall runoff models are still a big challenge in streamflow simulation. In this paper, a new technique using ANN to improve the accuracy of TOPMODEL is presented. TOPMODEL contains three sub-models, which are root storage, gravity storage and saturated storage. The proposed scheme is to replace one of the sub-models by artificial neural networks (ANN) model. A medium catchment located in tropical Malaysia known as Rantau Panjang catchment (RPC) is used. Two years, 1998-1999, are used for calibration, and 2000-2001 are used for validation process using daily data sets. Model results are evaluated by Nash-Sutcliffe model (NS), relative volume error (RVE) and correlation coefficient (CoC) which have been improved from 0.63 to 0.86, 0.92 to 0.93 and 40.91 to 14.12 respectively demonstrate the ability of ANN to improve the accuracy of TOPMODEL. It is concluded that the scheme can improve performance in terms of streamflow simulation.

Sizing a 3 kWp Retrofitted Grid-Connected Photovoltaic System: a Case Study in Tropical Malaysia

The work presents a tropical case study of sizing 3 kWp retrofitted grid-connected photovoltaic system (GCPV) installed in Klang, Malaysia. The sizing was based on customer’s budget requirement of RM 22, 500 and conducted through a designated mathematical approach. The mathematical approach involved technical aspects which aligns the voltage and current specifications of both PV array and inverter. Besides, this approach includes possible severe climatic condition of solar irradiance and ambient temperature variations. By implementing the sizing mathematical approach in this study, the final PV array configuration is 1 x 9 (1 parallel x 9 series). This study was also conducted to compare between the actual and the predicted energy yield to reflect customer satisfaction. Based on the result, the percentage differences are acceptable for February and March 2018. Interestingly, the percentage difference for January 2018 was over-predicted and the abnormality was suggested to be resulted from the inaccuracy of the Peak Sun Hour (PSH) estimation. In conclusion, this study is significant as an overview on the sizing and performance reliability of GCPV system in tropical Malaysia to meet up the customer satisfaction.Â

Identifying supportive daytime lighting characteristics for enhancing individuals’ psychophysiological wellbeing in windowless workplace in tropical Malaysia

Inappropriate architectural lighting exposures in workplaces are causing light-induced health and performance-related problems among healthy, urban individuals. This paper presents part one of an integrated tropical architectural lighting design framework for improving dayshift individuals’ psychophysiological wellbeing in windowless workplace in Malaysia. The paper discusses five architectural lighting factors, namely intensity, spectrum, timing, duration, spatial distribution. The daytime lighting characteristics that influence individuals’ psychophysiological wellbeing indicators (IPWI) were analysed. Findings indicated a dearth of literature in the lighting characteristics to support IPWI in the tropics, as evidence was predominantly from seasonal climate contexts. This motivated a critical discussion on the lighting factors and recommendations of alternative design consideration for a tropical Asian context. Potential daytime architectural lighting characteristics likely to support dayshift IPWI in windowless workplace in tropical Malaysia were also recommended for further investigations. These recommendations in the framework are expected to facilitate healthier windowless workplace design in Malaysia.

Establishment of Standard Reference Environment for Photovoltaic Nominal Operating Cell Temperature Testing with Dedicated Approach for Tropical Region

<p>This paper presents the establishment of Standard Reference Environment (SRE) for photovoltaic (PV) Nominal Operating Cell Temperature (NOCT) testing in Malaysia representing one of the countries that lies in tropical region. From a field testing conducted, 12-months data of six parameters namely solar irradiance (SI), ambient temperature (AT), relative humidity (RH), wind speed (WS), wind direction (WD), module temperature (MT) and open circuit voltage were analysed to determine the median SI and the median AT. From the analysis, the median SI and the median AT are 228 W/m<sup>2 </sup>and 30 °C respectively. However, these results show that the current approach in determining SRE using median ambient parameters is not suitable for tropical Malaysia based on the percentage error of approximately 30 %. Due to this, the proposed approach applied in this study is determining the corresponding AT of the same SI (800 W/m<sup>2</sup>) used in present SRE of international standard. Thus, the new proposed SI and AT for SRE in this study are 800W/m<sup>2</sup> and 31°C respectively. The SRE found in this study is determined using dedicated approach to suit tropical climate in deriving a more accurate NOCT for tropical region.<em></em></p>

Ecological Urbanism in the Tropics Studies on the Sustainable Dimensions of Malay Traditional Urban Centers

Many of the present eco-cities are designed and planned with an emphasis on high technology and infrastructure yet the meaning of sustainability itself implies a balance between past and present. Past urban configurations that rise from earlier traditional socio-cultural structures reflect sustainable principles localised to climate and ecology. The aim of this study is to reconstruct urban morphologies be-fore the advent of the automobile in order to analyse and characterise urban forms that are aligned with ecological criteria such as walk-ability, permeability and shade. Three traditional urban center or ‘cores’ in tropical Malaysia which had reigned during the early colo-nial era yet still related sultanate-based polities are mapped in terms of morphologies and these urban ‘core’ configurations were esti-mated and composed according to historical documents and evidences . These urban patterns are then discussed with regards to the present principles and criteria of green urbanism. The reconstructed and mapped urban cores are discussed in relation to green urban-ism principles and criteria, namely, based on global sustainable standards namely the LEED ND (Leadership in Energy and Environ-mental Design) version 4 neighbourhood rating system. The findings from this study suggest the contextualization of sustainable criteria according to climate and postulate the differences between traditional urban morphologies that can further regionalism principles of current green urbanism and further contextualise key principles in international standards on urbanism.

Tupistra cardinalis (Asparagaceae), a new species from limestone areas in northern Vietnam

Tupistra Ker Gawler (1814: 1655), which was later recircumscribed by Tanaka (2003a, 2010a), belongs to Nolinoideae of Asparagaceae (APG 2009, Chase et al. 2009). It comprises about 30 species (Tanaka 2010a, Averyanov et al. 2017, Govaerts 2017, Nguyen et al. 2017, Roy et al. 2017, Tanaka et al. 2017) distributed widely over subtropical to tropical Asia, covering Bangladesh, Bhutan, China, India, Indonesia, Laos, Malaysia, Myanmar, Nepal, Thailand, and Vietnam (Tanaka 2010a, Averyanov & Tanaka 2012, Hu et al. 2013, Vislobokov et al. 2014, Averyanov et al. 2015, 2016, 2017, Nguyen et al. 2017, Roy et al. 2017).

AN ECOLOGICAL STUDY ON A NOXIOUS WEED, PARTHENIUM HYSTEROPHORUS L AND ITS MANAGEMENT IN MALAYSIA IN 2015

Parthenium hysterophorus L., commonly known as Parthenium weed is an invasive weed and was first reported in Malaysia in 2013. This alien weed is now found in many parts of the country but it has not been recorded in Kelantan, Terengganu and Pahang in Peninsular Malaysia and Sarawak in East Malaysia. The plant also produces chemical compounds of Parthenin and other phenolic acids in all parts of the plant, including hair-like structure (trichomes) on the stems and leaves and pollens, that are highly toxic to human and animals. In tropical Malaysia, the natural vegetation grows well and has been observed to suppress and contained the spread of Parthenium weed. Several species of grasses, broadleaved plants and sedges are able to co-exist with Parthenium weed. Human activities viz. urban development, agriculture, over-grazing, etc., create a conducive environment for Parthenium to establish. Weed management involves the following measures: i) import regulation, ii) legislation, iii) early detection and eradication, iv) manual weeding, and v) chemical control. Common salt and several herbicides have been found to give effective control. The overall status of Parthenium weed is discussed and recommendations are given to deal with its infestation and eradication. Keywords: Parthenium hysterophorus, invasive weed, toxic weed, weed management, control and eradication

Kuppameni: A Potent Herbal Boon for Undernourished Malaysian Indian Plantation Workers

KEYWORDS Herbal Benefit. Plant Extract. Tropical. Nutrient. Alternative Drug ABSTRACT Malaysian Indian plantation workers are economically deprived and suffer from malnutrition. This can be altered by consuming medicinal and nutritional herbs found aplenty in tropical Malaysia. The herb acalypha indica linn, or Indian nettle, which has high antioxidants, is of particular interest for Indian estate workers. Antioxidants in the plant help retard toxic free radicals found in the body. Considered an indigenous form of healthcare, consuming this plant on a regular basis has the potential to rejuvenate the health of the under-nourished Indian plantation worker.

Temperature and Precipitation Changes and Possible Threats to Crop Production in Arid, Semi-arid and Tropical Forest Environment

Changing climate presents one of the most challenging threats to food crop production throughout the agro-ecologies. Annual food crops on which we rely most on are sensitive to temperature and precipitation change as it not only affects the temperature and moisture of the surroundings but affects the levels in soils as well. While climate change will have global impacts on crop production, regional variation will be play significant role in tackling climate change problem. This study examines 10-30 years data on the regional variation in temperature and precipitation from one location each in Arid and semi-Arid climate, one location in Dry sub-Humid climate and six locations in the Tropical Forest climate. The data collected were critically analysed using 5-10 years moving average plots, linear trend analysis and t-test using SPSS® software. Depending on the location, results showed significant (P<0.05) increase in temperature ranging from 0.015-0.045oC. Increase was mostly in the last 5-10 years compared to 1983-1990. Also, this increment was higher in semi-Arid & Dry-humid climate (0.044-0.087oC) than in Tropical rainforest where the increase was 0.015oC. No significant (P>0.05) increase in temperature was observed in the Arid climate in the last 10 years. In tropical rainforest climate, increase in temperature (0.044oC) was higher in the metropolis area than the countryside. From the locations examined in this study, there was no significant change in the precipitation pattern in the last 10-30 years. Simple plots overlaying temperature changes on crop production data revealed mixed response. Groundnut (Arachis hypogea), Bambara groundnut (Vigna subterannea) and hungry rice (Digeteria exilis) showed tolerance to increased temperatures in the Semi-Arid tropics. Rice (Oryza sativa) in Tropical Malaysia showed increased in yield with temperature. What may be important to note here is the resilience of the genotypes to temperature changes so that these genotypes could be further studied for adaptation to climate change. No doubt that there is evidence of increase in temperature, regional variations will exist and will play an important role in mitigating climate change.

Potentiality of Roselle and Onion (Allium cepa) peel as Raw Materials for Producing Protocatechuic Acid in Tropical Malaysia: A Comparative Study

Protocatechuic acid from natural sources are widely used in human health. This study focuses on the presence of protocatechuic acid (PCA) in Rosselle ( Hibiscus sabdariffa ) and onion peel ( Allium cepa ). Collection of onion peel is difficult and amount is less than 1% in onion. Moreover, Malaysia is importing 100% from overseas. On the contrary, roselle is very common in tropical Malaysia and its calyx can be dried and preserved. Thin Layer Chromatography (TLC) and High Performance Liquid Chromatography (HPLC) were used to identify protocathechuic acid (PCA) from the samples. TLC was performed on 20×20 cm Silica gel 60 F 254 aluminum sheets as TLC plates with mixtures of water-methanol-formic acid as mobile phase. TLC recorded the presence of protocatechuic acid in both of the samples. HPLC analysis was performed on C-18 in 250×4.6 mm steel column with methanol-water-formic acid in 25:75:0.5 ratio as mobile phase. The flow rate of the mobile phase was 1.0 ml/min and protocatechuic acid was detected at 260 nm of wavelength. The quantities of protocatechuic acid determined by HPLC in rosselle and onion peel were 0.014 mg in 30 g of dried samples extract and 0.25 mg in 30 g of dried extract, respectively. The amount of protocatechuic acid in onion peel extract was eighteen times higher compared to Rosselle extract but considering availability of raw materials in Malaysia, roselle might be used as good source of PCA production with potential economic feasibility.